This invention relates to elongated hinges of the type generally referred to as piano hinges and more particularly is directed to an improved non-metallic composite hinge having an integral structure and of high strength and corrosion resistance.
Piano hinges are used to a substantial degree in the aircraft industry in commercial and military aircraft for supporting swingable components, particularly doors. However, heretofore, such piano hinges have been constructed largely of metallic components which are not compatible with recently developed composite structural components, e.g. constructed of graphite-epoxy materials, with which such piano hinges are to be employed. Moreover, such components have the disadvantage of having high weight and also are subject to corrosion.
U.S. Pat. No. 4,231,135 is directed to a piano hinge formed of elongated flexible flange portions, each of which includes a plurality of integral aligned knuckles which engageably cooperate with the knuckles in the other, whereby a pin can be passed through the knuckles of each flange portion forming an elongated hinge. The flanges are extruded in a flaxible and pliable material such as vinyl plastic. The hinge pin can comprise a flexible material. The piano hinge of the patent is particularly designed for use in the cushion and furniture industry so that it can be sewn to fabric or other flexible material.
U.S. Pat. No. 4,175,315 discloses an all plastic hinge formed of plastic molded hinge halves and a molded hinge pin.
U.S. Pat. No. 3,650,050 discloses a hinge exhibitor comprising hinge leaves and hinge knuckles formed of a transparent plastic material such as polycarbonate.
U.S. Pat. No. 3,703,742 is also directed to a plastic hinge and U.S. Pat. No. 3,499,183 discloses a hinge having metallic elements and plastic hinge knuckle bushings.
However, the plastic hinges of the prior art as exemplified by the hinges disclosed in the above patents are generally unsuitable for use in the aircraft industry where high strength and low weight are particularly important.
It is accordingly one object of the invention to provide an improved composite piano hinge.
Another object is the provision of a light weight composite piano hinge particularly useful as an aircraft structural component.
A still further object of the invention is to provide a composite piano hinge having an integral structure and of high strength and having particular utility for use in commercial and military aircraft, in conjunction with compatible structural components thereof, such as composite doors, and the like.
Yet another object is the provision of procedure for producing the above composite piano hinge.